Answer:
One mRNA.
Explanation:
In bacteria, genes which are related to each other are found in cluster on the chromosome and mostly transcribed in a single unit from one promoter.
There are three genes present in lac operon which are lac Z, lac Y, and lac A. Under the control of one promoter, these genes transcribed in a single mRNA.
Then mRNA translated into proteins which help in utilization of lactose.
